On Fri, Sep 12, 2025 at 03:07:00PM +0200, Paolo Abeni wrote:
> Extend the VirtioDeviceFeatures struct with an additional u64
> to track unknown features in the 64-127 bit range and decode
> the full virtio features spaces for vhost and virtio devices.
>
> Also add entries for the soon-to-be-supported virtio net GSO over
> UDP features.
>
> Reviewed-by: Akihiko Odaki <[email protected]>
> Acked-by: Jason Wang <[email protected]>
> Signed-off-by: Paolo Abeni <[email protected]>
> ---
> v3 -> v4:
> - cleanup unknown features init
> - update QMP example and doc accordingly
> - use new virtio_features macro names
>
> v2 -> v3:
> - unknown-dev-features-dword2 -> unknown-dev-features2
> - _array -> _ex
> - fixed typos in entries description
>
> v1 -> v2:
> - uint128_t -> uint64_t[]
> ---
> hw/virtio/virtio-hmp-cmds.c | 3 +-
> hw/virtio/virtio-qmp.c | 91 +++++++++++++++++++++++++------------
> hw/virtio/virtio-qmp.h | 3 +-
> qapi/virtio.json | 9 +++-
> 4 files changed, 74 insertions(+), 32 deletions(-)
>
> diff --git a/hw/virtio/virtio-hmp-cmds.c b/hw/virtio/virtio-hmp-cmds.c
> index 7d8677bcf0..1daae482d3 100644
> --- a/hw/virtio/virtio-hmp-cmds.c
> +++ b/hw/virtio/virtio-hmp-cmds.c
> @@ -74,7 +74,8 @@ static void hmp_virtio_dump_features(Monitor *mon,
> }
>
> if (features->has_unknown_dev_features) {
> - monitor_printf(mon, " unknown-features(0x%016"PRIx64")\n",
> + monitor_printf(mon, "
> unknown-features(0x%016"PRIx64"%016"PRIx64")\n",
> + features->unknown_dev_features2,
> features->unknown_dev_features);
> }
> }
> diff --git a/hw/virtio/virtio-qmp.c b/hw/virtio/virtio-qmp.c
> index 3b6377cf0d..502c9ae930 100644
> --- a/hw/virtio/virtio-qmp.c
> +++ b/hw/virtio/virtio-qmp.c
> @@ -325,6 +325,20 @@ static const qmp_virtio_feature_map_t
> virtio_net_feature_map[] = {
> FEATURE_ENTRY(VHOST_USER_F_PROTOCOL_FEATURES, \
> "VHOST_USER_F_PROTOCOL_FEATURES: Vhost-user protocol features "
> "negotiation supported"),
> + FEATURE_ENTRY(VIRTIO_NET_F_GUEST_UDP_TUNNEL_GSO, \
> + "VIRTIO_NET_F_GUEST_UDP_TUNNEL_GSO: Driver can receive GSO over "
> + "UDP tunnel packets"),
> + FEATURE_ENTRY(VIRTIO_NET_F_GUEST_UDP_TUNNEL_GSO_CSUM, \
> + "VIRTIO_NET_F_GUEST_UDP_TUNNEL_GSO: Driver can receive GSO over "
This really should be VIRTIO_NET_F_GUEST_UDP_TUNNEL_GSO_CSUM.
Given they all seem to start with repeating the feature name,
why not just add it to the string automatically by the macro?
> + "UDP tunnel packets requiring checksum offload for the outer "
> + "header"),
> + FEATURE_ENTRY(VIRTIO_NET_F_HOST_UDP_TUNNEL_GSO, \
> + "VIRTIO_NET_F_HOST_UDP_TUNNEL_GSO: Device can receive GSO over "
> + "UDP tunnel packets"),
> + FEATURE_ENTRY(VIRTIO_NET_F_HOST_UDP_TUNNEL_GSO_CSUM, \
> + "VIRTIO_NET_F_HOST_UDP_TUNNEL_GSO: Device can receive GSO over "
> + "UDP tunnel packets requiring checksum offload for the outer "
> + "header"),
> { -1, "" }
> };
> #endif
> @@ -510,6 +524,24 @@ static const qmp_virtio_feature_map_t
> virtio_gpio_feature_map[] = {
> list; \
> })
>
> +#define CONVERT_FEATURES_EX(type, map, bitmap) \
> + ({ \
> + type *list = NULL; \
> + type *node; \
> + for (i = 0; map[i].virtio_bit != -1; i++) { \
> + bit = map[i].virtio_bit; \
> + if (!virtio_has_feature_ex(bitmap, bit)) { \
> + continue; \
> + } \
> + node = g_new0(type, 1); \
> + node->value = g_strdup(map[i].feature_desc); \
> + node->next = list; \
> + list = node; \
> + virtio_clear_feature_ex(bitmap, bit); \
> + } \
> + list; \
> + })
> +
> VirtioDeviceStatus *qmp_decode_status(uint8_t bitmap)
> {
> VirtioDeviceStatus *status;
> @@ -545,109 +577,112 @@ VhostDeviceProtocols *qmp_decode_protocols(uint64_t
> bitmap)
> return vhu_protocols;
> }
>
> -VirtioDeviceFeatures *qmp_decode_features(uint16_t device_id, uint64_t
> bitmap)
> +VirtioDeviceFeatures *qmp_decode_features(uint16_t device_id,
> + const uint64_t *bmap)
> {
> + uint64_t bitmap[VIRTIO_FEATURES_NU64S];
> VirtioDeviceFeatures *features;
> uint64_t bit;
> int i;
>
> + virtio_features_copy(bitmap, bmap);
> features = g_new0(VirtioDeviceFeatures, 1);
> features->has_dev_features = true;
>
> /* transport features */
> - features->transports = CONVERT_FEATURES(strList, virtio_transport_map, 0,
> - bitmap);
> + features->transports = CONVERT_FEATURES_EX(strList, virtio_transport_map,
> + bitmap);
>
> /* device features */
> switch (device_id) {
> #ifdef CONFIG_VIRTIO_SERIAL
> case VIRTIO_ID_CONSOLE:
> features->dev_features =
> - CONVERT_FEATURES(strList, virtio_serial_feature_map, 0, bitmap);
> + CONVERT_FEATURES_EX(strList, virtio_serial_feature_map, bitmap);
> break;
> #endif
> #ifdef CONFIG_VIRTIO_BLK
> case VIRTIO_ID_BLOCK:
> features->dev_features =
> - CONVERT_FEATURES(strList, virtio_blk_feature_map, 0, bitmap);
> + CONVERT_FEATURES_EX(strList, virtio_blk_feature_map, bitmap);
> break;
> #endif
> #ifdef CONFIG_VIRTIO_GPU
> case VIRTIO_ID_GPU:
> features->dev_features =
> - CONVERT_FEATURES(strList, virtio_gpu_feature_map, 0, bitmap);
> + CONVERT_FEATURES_EX(strList, virtio_gpu_feature_map, bitmap);
> break;
> #endif
> #ifdef CONFIG_VIRTIO_NET
> case VIRTIO_ID_NET:
> features->dev_features =
> - CONVERT_FEATURES(strList, virtio_net_feature_map, 0, bitmap);
> + CONVERT_FEATURES_EX(strList, virtio_net_feature_map, bitmap);
> break;
> #endif
> #ifdef CONFIG_VIRTIO_SCSI
> case VIRTIO_ID_SCSI:
> features->dev_features =
> - CONVERT_FEATURES(strList, virtio_scsi_feature_map, 0, bitmap);
> + CONVERT_FEATURES_EX(strList, virtio_scsi_feature_map, bitmap);
> break;
> #endif
> #ifdef CONFIG_VIRTIO_BALLOON
> case VIRTIO_ID_BALLOON:
> features->dev_features =
> - CONVERT_FEATURES(strList, virtio_balloon_feature_map, 0, bitmap);
> + CONVERT_FEATURES_EX(strList, virtio_balloon_feature_map, bitmap);
> break;
> #endif
> #ifdef CONFIG_VIRTIO_IOMMU
> case VIRTIO_ID_IOMMU:
> features->dev_features =
> - CONVERT_FEATURES(strList, virtio_iommu_feature_map, 0, bitmap);
> + CONVERT_FEATURES_EX(strList, virtio_iommu_feature_map, bitmap);
> break;
> #endif
> #ifdef CONFIG_VIRTIO_INPUT
> case VIRTIO_ID_INPUT:
> features->dev_features =
> - CONVERT_FEATURES(strList, virtio_input_feature_map, 0, bitmap);
> + CONVERT_FEATURES_EX(strList, virtio_input_feature_map, bitmap);
> break;
> #endif
> #ifdef CONFIG_VHOST_USER_FS
> case VIRTIO_ID_FS:
> features->dev_features =
> - CONVERT_FEATURES(strList, virtio_fs_feature_map, 0, bitmap);
> + CONVERT_FEATURES_EX(strList, virtio_fs_feature_map, bitmap);
> break;
> #endif
> #ifdef CONFIG_VHOST_VSOCK
> case VIRTIO_ID_VSOCK:
> features->dev_features =
> - CONVERT_FEATURES(strList, virtio_vsock_feature_map, 0, bitmap);
> + CONVERT_FEATURES_EX(strList, virtio_vsock_feature_map, bitmap);
> break;
> #endif
> #ifdef CONFIG_VIRTIO_CRYPTO
> case VIRTIO_ID_CRYPTO:
> features->dev_features =
> - CONVERT_FEATURES(strList, virtio_crypto_feature_map, 0, bitmap);
> + CONVERT_FEATURES_EX(strList, virtio_crypto_feature_map, bitmap);
> break;
> #endif
> #ifdef CONFIG_VIRTIO_MEM
> case VIRTIO_ID_MEM:
> features->dev_features =
> - CONVERT_FEATURES(strList, virtio_mem_feature_map, 0, bitmap);
> + CONVERT_FEATURES_EX(strList, virtio_mem_feature_map, bitmap);
> break;
> #endif
> #ifdef CONFIG_VIRTIO_I2C_ADAPTER
> case VIRTIO_ID_I2C_ADAPTER:
> features->dev_features =
> - CONVERT_FEATURES(strList, virtio_i2c_feature_map, 0, bitmap);
> + CONVERT_FEATURES_EX(strList, virtio_i2c_feature_map, bitmap);
> break;
> #endif
> #ifdef CONFIG_VIRTIO_RNG
> case VIRTIO_ID_RNG:
> features->dev_features =
> - CONVERT_FEATURES(strList, virtio_rng_feature_map, 0, bitmap);
> + CONVERT_FEATURES_EX(strList, virtio_rng_feature_map, bitmap);
> break;
> #endif
> #ifdef CONFIG_VHOST_USER_GPIO
> case VIRTIO_ID_GPIO:
> features->dev_features =
> - CONVERT_FEATURES(strList, virtio_gpio_feature_map, 0, bitmap);
> + CONVERT_FEATURES_EX(strList, virtio_gpio_feature_map, bitmap);
> break;
> #endif
> /* No features */
> @@ -680,10 +715,9 @@ VirtioDeviceFeatures *qmp_decode_features(uint16_t
> device_id, uint64_t bitmap)
> g_assert_not_reached();
> }
>
> - features->has_unknown_dev_features = bitmap != 0;
> - if (features->has_unknown_dev_features) {
> - features->unknown_dev_features = bitmap;
> - }
> + features->has_unknown_dev_features = !virtio_features_empty(bitmap);
> + features->unknown_dev_features = bitmap[0];
> + features->unknown_dev_features2 = bitmap[1];
>
> return features;
> }
> @@ -743,11 +777,11 @@ VirtioStatus *qmp_x_query_virtio_status(const char
> *path, Error **errp)
> status->device_id = vdev->device_id;
> status->vhost_started = vdev->vhost_started;
> status->guest_features = qmp_decode_features(vdev->device_id,
> - vdev->guest_features);
> + vdev->guest_features_ex);
> status->host_features = qmp_decode_features(vdev->device_id,
> - vdev->host_features);
> + vdev->host_features_ex);
> status->backend_features = qmp_decode_features(vdev->device_id,
> - vdev->backend_features);
> + vdev->backend_features_ex);
>
> switch (vdev->device_endian) {
> case VIRTIO_DEVICE_ENDIAN_LITTLE:
> @@ -785,11 +819,12 @@ VirtioStatus *qmp_x_query_virtio_status(const char
> *path, Error **errp)
> status->vhost_dev->nvqs = hdev->nvqs;
> status->vhost_dev->vq_index = hdev->vq_index;
> status->vhost_dev->features =
> - qmp_decode_features(vdev->device_id, hdev->features);
> + qmp_decode_features(vdev->device_id, hdev->features_ex);
> status->vhost_dev->acked_features =
> - qmp_decode_features(vdev->device_id, hdev->acked_features);
> + qmp_decode_features(vdev->device_id, hdev->acked_features_ex);
> status->vhost_dev->backend_features =
> - qmp_decode_features(vdev->device_id, hdev->backend_features);
> + qmp_decode_features(vdev->device_id, hdev->backend_features_ex);
> +
> status->vhost_dev->protocol_features =
> qmp_decode_protocols(hdev->protocol_features);
> status->vhost_dev->max_queues = hdev->max_queues;
> diff --git a/hw/virtio/virtio-qmp.h b/hw/virtio/virtio-qmp.h
> index 245a446a56..e0a1e49035 100644
> --- a/hw/virtio/virtio-qmp.h
> +++ b/hw/virtio/virtio-qmp.h
> @@ -18,6 +18,7 @@
> VirtIODevice *qmp_find_virtio_device(const char *path);
> VirtioDeviceStatus *qmp_decode_status(uint8_t bitmap);
> VhostDeviceProtocols *qmp_decode_protocols(uint64_t bitmap);
> -VirtioDeviceFeatures *qmp_decode_features(uint16_t device_id, uint64_t
> bitmap);
> +VirtioDeviceFeatures *qmp_decode_features(uint16_t device_id,
> + const uint64_t *bitmap);
>
> #endif
> diff --git a/qapi/virtio.json b/qapi/virtio.json
> index 9d652fe4a8..05295ab665 100644
> --- a/qapi/virtio.json
> +++ b/qapi/virtio.json
> @@ -247,6 +247,7 @@
> # },
> # "host-features": {
> # "unknown-dev-features": 1073741824,
> +# "unknown-dev-features2": 0,
> # "dev-features": [],
> # "transports": [
> # "VIRTIO_RING_F_EVENT_IDX: Used & avail. event fields
> enabled",
> @@ -490,14 +491,18 @@
> # unique features)
> #
> # @unknown-dev-features: Virtio device features bitmap that have not
> -# been decoded
> +# been decoded (bits 0-63)
> +#
> +# @unknown-dev-features2: Virtio device features bitmap that have not
> +# been decoded (bits 64-127) (since 10.2)
> #
> # Since: 7.2
> ##
> { 'struct': 'VirtioDeviceFeatures',
> 'data': { 'transports': [ 'str' ],
> '*dev-features': [ 'str' ],
> - '*unknown-dev-features': 'uint64' } }
> + '*unknown-dev-features': 'uint64',
> + '*unknown-dev-features2': 'uint64' } }
>
> ##
> # @VirtQueueStatus:
> --
> 2.51.0
